/*
 * Copyright [2020] [MaxKey of copyright http://www.maxkey.top]
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 

/**
 * 
 */
package org.dromara.maxkey.util;

import java.util.Date;
import org.slf4j.LoggerFactory;

/**
 * 20位的流水号
 * 8位系统日期YYYYMMDD+2位节点号+6位时间戳为HHMMSS+4位顺序流水号。
 * 其中4位顺序流水号要求为“数值格式，位数不足左补零，各系统顺序生成”,为了避免顺序号重复，4位流水为该秒内的顺序流水，即每秒内每个节点最多1万笔交易
 * 
 * @author Crystal.sea
 *
 */
public class IdSequence {
    
    public static      String     OLD_DATETIME="";
    /**
     * 静态属性
     */
    public static int         STATIC_SEQUENCE=0;
    
    /**
     * 默认节点
     */
    public static String     DEFAULT_NODE_NUMBER="01";
    
    public static String     STATIC_NODE_NUMBER="--";
    
    /**
     * 生成20位的流水号
     * @return 流水号
     */
    public static synchronized String next(){
        String currentDateTime=getCurrentSystemDateTime();
        
        if(null==currentDateTime){
            LoggerFactory.getLogger(IdSequence.class).error("获取系统日期失败");
            return null;
        }
        
        StringBuffer sequenceNumber=new StringBuffer();
        
        sequenceNumber.append(currentDateTime.substring(0, 8));
        sequenceNumber.append(getNodeNumber());
        sequenceNumber.append(currentDateTime.substring(8));
        sequenceNumber.append(nextSequence());
        return sequenceNumber.toString();
    }
    
    public static final String initNodeNumber(String nodeNumbers){
        if(STATIC_NODE_NUMBER.equals("--")){
            if(null!=nodeNumbers&&!nodeNumbers.equals("")){
                
                String ipAddressConfigValue=nodeNumbers;
                LoggerFactory.getLogger(IdSequence.class).info("ARE config.node.number : "+ipAddressConfigValue);
                if(ipAddressConfigValue.indexOf(",")>-1){
                    
                    String hostIpAddress=MacAddress.getAllHostMacAddress();//获得本机IP
                    
                    LoggerFactory.getLogger(IdSequence.class).info("hostIpAddress : "+hostIpAddress);
                    
                    String []ipAddressValues=ipAddressConfigValue.split(",");
                    for(String ipvalue : ipAddressValues){
                        String[] ipNode=ipvalue.split("=");
                        if(ipNode!=null&&ipNode.length>0&&hostIpAddress.indexOf(ipNode[0])>-1){
                            STATIC_NODE_NUMBER=ipNode[1];
                        }
                    }
                    
                    if(STATIC_NODE_NUMBER.equals("--")){
                        LoggerFactory.getLogger(IdSequence.class).error("GET MAC BIND NODE ERROR . ");
                        STATIC_NODE_NUMBER=DEFAULT_NODE_NUMBER;
                    }
                    
                }else{
                    STATIC_NODE_NUMBER=nodeNumbers;
                }
                LoggerFactory.getLogger(IdSequence.class).info("STATIC_NODE_SEQUENCE_NUMBER : "+STATIC_NODE_NUMBER);
                if(STATIC_NODE_NUMBER.length()!=2){
                    LoggerFactory.getLogger(IdSequence.class).error("系统节点号必须2位");
                }
            }else{
                STATIC_NODE_NUMBER=DEFAULT_NODE_NUMBER;
            }
        }
        return STATIC_NODE_NUMBER;
    }
    
    public static final String getNodeNumber(){
        return STATIC_NODE_NUMBER;
    }
    /**
     * 同一时刻只有一个访问
     * @return
     */
    private static final  synchronized String nextSequence(){
        STATIC_SEQUENCE=(STATIC_SEQUENCE+1)%10000;
        return String.format("%04d", STATIC_SEQUENCE);
    }
    
    /**
     * 获取系统当前日期，格式为yyyyMMddHHmmSS
     * @return 当前系统日期
     */
    private static  synchronized String  getCurrentSystemDateTime(){
        String currentdatetime=null;
        synchronized(OLD_DATETIME)
        {
            currentdatetime=(new java.text.SimpleDateFormat("yyyyMMddHHmmss")).format(new Date());
            /**
             * 判断是否是新的时间，如果是新时间则STATIC_SEQUENCE从0开始计数
             */
            if(!currentdatetime.equals(OLD_DATETIME)){
                STATIC_SEQUENCE=0;
                OLD_DATETIME=currentdatetime;
            }
        }
        return currentdatetime;
    }
}
